JPH095477A - Impervious device for water storage container inner wall face - Google Patents

Abstract

PURPOSE: To efficiently conduct the inspection work without draining water in a water storage container. CONSTITUTION: An impervious box 10 opened at one side section is hung with a suspension wire 6, and a positioning electromagnet 17 is fitted on the impervious box 10. Seal packings 12, 13, 14 are triply fitted at the open end section of the impervious box 10 to form an inside small chamber 15 and an outside small chamber 16. Main operation lines 30, 31, 32 connected with an air ejector are connected at the bottom positions of the impervious box 10, inside small chamber 15, and outside small chamber 16, and an Ar gas line is connected to the main operation lines 30, 31, 32. Auxiliary operation lines 51, 52, 53 communicated with the atmospheric air are connected at proper positions of the impervious box 10, inside small chamber 15, and outside small chamber 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for holding water in a nuclear power plant, a chemical plant, etc. It relates to a water blocking device for the inner wall surface of the water holding container used in.

[0002]

2. Description of the Related Art For example, a reactor pressure vessel is a water holding vessel used in a state where water (reactor water) is stored inside. Nozzles such as cooling water inlet nozzles and outlet nozzles are provided on the side wall of such a reactor pressure vessel, but at these nozzle portions, remodeling work such as replacing the pipes connected to the nozzles is required. It may cost.

In the case of modifying the nozzle portion of the above reactor pressure vessel, water is contained in the vessel, and it has been heretofore known to prevent water from leaking out during the modification work so that the modification work cannot be performed. The water has been stopped by draining water from the reactor pressure vessel or by inserting a plug with a packing or tube inside the nozzle to pressurize the packing or tube.

[0004]

However, in the case of the above-mentioned method of draining water, there is a problem that not only a large amount of water must be handled but also it takes a long time to supply and drain water.
On the other hand, the method of inserting the plug into the nozzle may not be able to completely stop the water, and it is difficult to check the working status, and if the weld between the nozzle and the pipe is very close to the container, It may not be possible to set the plug in the nozzle,
Furthermore, there is a problem that the method of supplying Ar gas must be separately considered.

Therefore, according to the present invention, not only the modification of the nozzle provided in the water holding container but also the inspection work of the welded portion of the inner wall surface of the water holding container can be surely performed without draining water. It is intended to provide a water blocking device for the inner wall surface of the water holding container.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a water shield box having one side open, a support plate fixed to the peripheral portion of the water shield box on the open end side, and a water shield. A plurality of stages are formed on the support plate so that a plurality of ring-shaped small chambers having different diameters are formed between the inner wall surface and the support plate so as to be in contact with the inner wall surface of the holding container and between the inner wall and the support plate. Sealing packing attached to the above, a positioning electromagnetic magnet mounted on the upper part of the water shield box, a main operation line connecting one end to each of the water shield box, the inner small chamber and the outer small chamber, and each of these main operation lines The air ejector connected to the other end of the water shield box, the sub-operation line connecting the water shield box, the inner small chamber, and the outer small chamber to one end and opening the other end to the atmosphere, respectively. The water blocking device body comprising a CCD camera and a lighting device, a configuration which is adapted to suspension supported on the take-up and down enables the the hanging wire.

An Ar gas line is connected in the middle of the main operation line connected to the water shield box and the inner small chamber.

[0008]

[Operation] After moving the water shield device body to the specified position in the water holding container, the water shield box is positioned by the electromagnetic magnet, and then the water in the water shield box is drawn out by the air ejector through the main operation line. Then, the impermeable box is pressed against the inner wall surface of the container by the water head pressure, and the sealing property is secured by the sealing packing. Furthermore, even after the water in the water shield box is drained, if the inside of the outer small chamber formed in the seal packing is continuously evacuated, the water that has entered through the outer seal packing is discharged. It is possible to maintain the sealing property. The inner wall surface of the container that is shielded by the water shield box can be inspected with a CCD camera.

Further, if Ar gas is supplied from the Ar gas line into the water shield box and inside the small chamber to make the inside of the water shield box an Ar gas atmosphere, the back wave welded portion during the nozzle remodeling work is improved. Oxidation will be prevented.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an overall view of an embodiment of the present invention adopted for a nozzle 2 provided on a side wall of a reactor pressure vessel 1 as a water holding vessel. 3 is provided with a lifting jig 5 on the refueling cart 4 equipped on the water refueling carriage 4, and a water blocking apparatus main body 7 hung from the lifting jig 5 so as to be able to be wound up and down is passed through a storage pool 8. It shows a state in which water (reactor water) 9 is submerged in the reactor pressure vessel 1 and set at the position of the nozzle 2.

The water-impervious device body 7 is constructed as shown in an enlarged view in FIG. That is, the support plate 1 having a continuous shape is provided around the open end side (front surface side) of the water shield box 10 having a required size with one side surface which is the front surface side opened.
1 is fixed so as to project inward and outward in the radial direction of the water shield box 10, and an inner wall surface of the reactor pressure vessel 1 is abutted on an inner wall surface of the reactor pressure vessel 1 on the front side surface of the support plate 11. A small-diameter inner seal packing 12 and a larger intermediate seal packing 13 so that a plurality of ring-shaped small chambers having different diameters are formed between the wall surface and the support plate 11.
And a large-diameter outer seal packing 14 are attached in three steps (triple) at a required interval, and each seal packing 1
By bringing 2, 13, and 14 into contact with the inner wall surface of the reactor pressure vessel 1, an inner small chamber 15 is provided between the inner seal packing 12 and the intermediate seal packing 13, and
Outer seal packing 14 and intermediate seal packing 13
And the outer small chambers 16 are formed between them. An electromagnetic magnet 17 for positioning the water shield box 10 on the inner wall surface of the reactor pressure vessel 1, a holding plate 19, and a mounting bracket 20 are provided on the water shield box 10.
Through. That is, the electromagnetic magnet 17
The holding plate 19 for holding the above is supported by a mounting bracket 20 fixed upward on the water shield box 10 so as to be displaceable in a direction in which the holding plate 19 is moved toward and away from the inner wall surface of the reactor pressure vessel 1 via a support rod 21, A spring 18 is interposed between the bracket 20 and the holding plate 19 for urging the electromagnetic magnet 17 so as to push the electromagnetic magnet 17 toward the inner wall surface of the reactor pressure vessel 1. Further, a CCD camera 22 is provided in the central portion on the back side of the water shield box 10 as described above.
0 to equip the inside of the water shield box 10 with the aerial lighting device 23 on the rear inner wall surface of the water shield box 10, and the water shield box 1
The underwater lighting device 24 is mounted on the upper part of the zero. 25 is the CCD camera 22 and the air lighting device 2
3, a power supply cable to the underwater lighting device 24, and 26 is a pipe connected to the nozzle 2.

At the bottom of the water-blocking device body 7, as shown in FIGS. 2 and 3, the water-blocking box 10, the inner small chamber 15 and the outer small chamber 16 are opened and closed in the middle.
And main operating line (hose) 30 with 28 and 29 respectively
, 31 and 32 are connected to respective one ends of the main operation lines 30, 31 and 32, and the other ends of the main operation lines 30, 31 and 32 are connected to respective suction portions of the air ejectors 33, 34 and 35, and the air ejectors 33 and 34 are connected. And each air introduction part of 35,
Connected to a pressurized air source 42 via air lines 39, 40 and 41 equipped with on-off valves 36, 37 and 38, respectively, on the way,
By driving each of the air ejectors 33, 34 and 35, the water in the water shield box 10, the inner small chamber 15 and the outer small chamber 16 can be discharged through the main operation lines 30, 31 and 32. An Ar gas supply source 45 is connected to a position of the lines 30 and 31 closer to the water shield apparatus main body 7 side than the opening / closing valves 27 and 28 via Ar gas lines 46 and 47 equipped with operation valves 43 and 44, respectively. Gas line 4
6 and 47, water shield box 10 through main operation lines 30 and 31
Ar gas can be supplied into the inner and inner small chambers 15. In addition, the impermeable box 10 and the inner small chamber 15
And one end of sub-operation lines (hoses) 51, 52 and 53, which are provided with open / close valves 48, 49 and 50 in the middle and are connected to the upper position of the outer small chamber 16 and the other end to the atmosphere, respectively. By opening / closing the opening / closing valves 48, 49, 50, the inside of the water shield box 10, the inside small chamber 15, the outside small chamber 1
6 and the atmosphere can be made to communicate with each other or to be shut off, and the open / close valve 48 of the sub operation lines 51 and 52
And 49, oxygen concentration measuring devices 54 and 55 are provided at positions on the atmosphere side, respectively, and the oxygen concentration measuring devices 54 and 55 can measure the oxygen concentration in the sub-operation lines 51 and 52. Reference numerals 56, 57 and 58 denote vacuum pressure gauges.

Now, for example, when performing a modification work of the nozzle 2 part such as replacing the pipe 26 connected to the nozzle 2 of the reactor pressure vessel 1 containing the water 9 as shown in the drawing, first, As shown in FIG. 1, the water shield apparatus main body 7 suspended by the suspension wire 6 is suspended from the suspension jig 5 on the refueling carriage 4 and is sunk into the reactor pressure vessel 1, and the water shield box 10 After moving the opening on the front side to the position corresponding to the nozzle 2, the electromagnetic magnet 17 is excited to energize the water shield box 1.
0 is fixed to the inner wall surface of the reactor pressure vessel 1. At this time, the underwater lighting device 24 in the water shield box 10 illuminates, and the CCD camera 22 is used to make the water shield box 10 correspond to the position of the nozzle 2. As a result, the sealing packings 12, 13 and 14 are brought into contact with the inner wall surface of the reactor pressure vessel 1 at the position surrounding the nozzle 2.

After the position of the water shield box 10 is fixed by the electromagnetic magnet 17, the opening / closing valves 49, 50 of the sub-operation lines 52, 53.
Open and open / close valves 28, 2 of main operation lines 31, 32
9 is opened and the opening / closing valves 37 of the air lines 40 and 41,
38 is opened to drive the air ejectors 34 and 35, so that the water 9 in the inner small chamber 15 and the outer small chamber 16 of the water-blocking device body 7 is discharged.
At the time when the water 9 is no longer discharged from the air ejectors 34 and 35, the opening / closing valves 49 and 49 of the sub operation lines 52 and 53,
By closing 50, the inside small chamber 15 and the outside small chamber 16 are made to have a negative pressure, preferably a vacuum pressure. By this operation, the sealing packings 12, 13 and 14 forming the small chambers 15 and 16 are pressed against the inner wall surface of the reactor pressure vessel 1, so that the sealing property is obtained. Even after the inside small chamber 15 and the outside small chamber 16 are evacuated, the inside small chamber 16 is evacuated.

Next, the opening / closing valve 48 of the sub operation line 51 is opened, and the opening / closing valve 27 of the main operation line 30 is opened.
Open the on-off valve 36 of the air line 39 to open the air ejector 3
The water 9 in the water shield box 10 is discharged by driving the water shield box 3. When the water 9 is discharged from the water shield box 10,
The impermeable box 10 is pressed by the head pressure of the water 9 in the reactor pressure vessel 1, so that the impermeable box 10 can be further sealed. When the water shield box 10 is strongly pressed against the inner wall surface of the reactor pressure vessel 1, the sealing packings 12, 13,
14 deforms to increase the contact area with the inner wall surface of the container, but at this time, the electromagnetic magnet 17 for fixing the water shield box 10
Since the spring is pressed by the spring 18, the pressing displacement of the water shield box 10 can be absorbed. Incidentally, if the size of the side plate of the water shield box 10 is, for example, 50 cm × 50 cm and the head is 10 m, the pressing force is F = 50 cm × 50 cm × 1 kg / cm ² = 2500 kg.

As described above, when the water in the water shield box 10 is drained, the air is illuminated by the aerial lighting device 23 in the water shield box 10, and the nozzle 2 is monitored while being monitored by the CCD camera 22.
The pipe 26 connected to is cut, and then a new pipe 26 is attached. At this time, a water-soluble sealant 59 is attached in the new pipe 26 as shown by a chain double-dashed line in FIG. Then, the opening / closing valves 48, 49 of the sub operation lines 51, 52 are opened, and the opening / closing valves 27, 28 of the main operation lines 30, 31 are closed, and the operation valves 43, 44 of the Ar gas lines 46, 47 are opened. Open, Ar gas is supplied from the Ar gas supply source 45 through the Ar gas lines 46 and 47 and the main operation lines 30 and 31 into the water shield box 10 and the inner small chamber 15, and the back of the pipe joint to the nozzle 2 is supplied. Wave welding is performed in an Ar gas atmosphere to prevent oxidation. In this case, A
The confirmation of the r gas atmosphere is performed by measuring the oxygen concentration with the oxygen concentration measuring devices 54 and 55 provided in the sub operation lines 51 and 52. Even if the water 9 enters through the outer seal packing 14 during the above welding work, the outer small chamber 16 continues to be evacuated as described above, so that the sealability of the water shield box 10 is improved. Can be secured.

When the modification of the nozzle 2 is completed, the on-off valves 27, 28, 29 of the main operation lines 30, 31, 32 are all closed, and the on-off valves 48, 49 of the auxiliary operation lines 51, 52, 53 are placed. Be sure to open all 50. As a result, the inside of the water shield box 10, the inner small chamber 15, and the outer small chamber 16 all become atmospheric pressure, and the pressing force against the container inner wall of the water shield box 10 is weakened.
After demagnetizing 7, the suspending wire 5 is wound up by the suspending jig 5 so that the water shield apparatus main body 7 can be pulled up and collected. At this time, even if the suspension wire 6 is wound up, the water shield box 10
If the water does not separate from the inner wall surface of the container,
Ar gas may be supplied under pressure into the water shield box 10 or the inner small chamber 15.

In this way, the nozzle 2 part can be efficiently modified without draining the water 9 from the reactor pressure vessel 1.

In the above embodiment, as an example, the nozzle 2 portion provided on the side wall of the reactor pressure vessel 1 is modified. However, the present invention is not limited to this. Instead, for example, the necessary inspection work of the inner wall surface of the reactor pressure vessel 1 including the inspection of the corrosion state of the welded portion exposed on the inner wall surface portion of the reactor pressure vessel 1
This can be done by making full use of the CCD camera 22 and the illumination devices 23 and 24 provided in 0. In this case,
1 can be moved to a place other than the nozzle 2 as shown by the chain double-dashed line in FIG. 1, and can be used for inspection work at all points on the inner wall surface of the reactor pressure vessel 1.

Further, in the embodiment, an example in which the water holding container is applied to the reactor pressure vessel 1 is shown, but the present invention is not limited to this, and other various changes may be made within the scope not departing from the gist of the present invention. Of course, it can be added.

[0022]

As described above, according to the water blocking apparatus for the inner wall surface of the water holding container of the present invention, the water blocking box can be moved to a desired position and positioned on the inner wall of the container by the electromagnetic magnet. , The inside of the inner small chambers formed in the plurality of sealing packings and the inside of the outer small chambers are drained by an air ejector to make each chamber have a negative pressure so that the sealing packings are brought into close contact with the inner wall surface of the container. Moreover, by removing the water from the water shield box with an air ejector, the water shield box can be pressed against the inner wall surface of the container by the water pressure in the water holding container. Since it is equipped with a camera and lighting equipment, the inside of the water shield box can be made watertight so that the inner wall surface can be partially shielded. Nozzle modification work and welding part inspection work can be performed between them. Moreover, the above-mentioned work such as nozzle part modification and container inspection can be confirmed using the lighting device in the water shield box and CCD camera. Since it can be done while doing so, you can check the mounting position of the water shield box and set it at an appropriate position, you can also check the work place and improve the accuracy of the work. Even if water enters from the outer seal packing part, the water sealability of the water shield box can be ensured by keeping the outer small chamber evacuated, so it is highly reliable. Since Ar gas can be supplied to the inside of the water shield box and inside the small chamber to create an Ar gas atmosphere inside the water shield box, it is possible to prevent oxidation of the backside weld when the nozzle is modified. It is possible to exert excellent effects and the like.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a water blocking device for an inner wall surface of a water holding container of the present invention.

FIG. 2 is an enlarged cross-sectional view showing details of the water blocking apparatus body in FIG.

FIG. 3 is a schematic diagram showing an overall system of the water blocking device for the inner wall surface of the water holding container of the present invention.

[Explanation of symbols]

 1 Reactor Pressure Vessel (Water Retaining Vessel) 2 Nozzle 6 Suspended Wire 7 Water Impermeable Device Body 9 Water 10 Water Impermeable Box 11 Support Plate 12 Inner Seal Packing 13 Intermediate Seal Packing 14 Outer Seal Packing 15 Inner Small Chamber 16 Outer Small Chamber 17 Electromagnetic magnet 22 CCD camera 23 Air illuminator 24 Underwater illuminator 30, 31, 32 Main operation line 33, 34, 35 Air ejector 46, 47 Ar gas line 51, 52, 53 Sub operation line

Claims (2)

[Claims] 1. A water shield box having one side surface opened, a support plate fixed to a peripheral portion of the water shield box on an open end side, and an inner wall surface of the water holding container abutting the inner wall surface and the support. Sealing packings attached to the support plate in multiple stages so that a plurality of ring-shaped small chambers having different diameters are formed between the plate and the inner side in the radial direction Positioning electromagnetic magnet, main operation line connecting one end to each of the water shield box, inner small chamber and outer small chamber, air ejector connected to the other end of each main operation line, and the water shield box and inner side Water shield apparatus main body comprising a sub-operation line in which one end is connected to each of the small chamber and the outer small chamber and the other end is opened to the atmosphere, and a CCD camera and an illumination device mounted in the water shield box. A water blocking device for an inner wall surface of a water holding container, characterized in that the water holding device is configured to be suspended and supported by a suspension wire that can be wound up and down. 2. An Ar gas line is connected in the middle of a main operation line connected to the water shield box and the inner small chamber.
Impermeable device for the inner wall surface of the water holding container described.